Gas Heat ESCO Exam Questions and Correct
Answers 100% Pass
Question 1
Induce draft furnaces have a vent safety switch that should open at ...?
Correct Answer
140 F
Question 2
A GFCI circuit breaker detects:
Correct Answer
current leaks to ground
Question 3
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof,
should...?
Correct Answer
Point down
Question 4
The proper name of the tool used to clean the inside edge of steel pipe is a:
Correct Answer
reamer
Page 1 of 41
,Question 5
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is:
Correct Answer
Temperature on/ Temperature off
Question 6
Burning one cubic foot of natural gas will produce approximately ___ BTU's.
Correct Answer
900-1100
Question 7
What is the purpose of a spoiler screw located on a burner, or adjustable-shutters?
Correct Answer
to mix primary air and gas
Question 8
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor:
Correct Answer
18 inches
Question 9
How much current does a typical flame sensor produce?
Correct Answer
1-30 microamps
Page 2 of 41
,Question 10
The proper name of the tool used to cut the threads of a steel pipe is a:
Correct Answer
die
Question 11
Natural gas piping must be sized to prevent excessive pressure drops. The National
Fuel Gas Code maximum pressure drop allowance is approximately:
Correct Answer
0.35 in WC
Question 12
An inclined manometer measures:
Correct Answer
pressures below 1 in. WC
Question 13
Furnace limit switches are wired in series with the:
Correct Answer
Gas valve
Question 14
While evaluating a gas valve that failed to open, the technician determined that; the
gas valve knob was in the proper position- the thermostat was calling for heat- the
valve is an electric ignition type- continuity of the main gas valve coil was good- and
proper voltage was present at the main gas valve coil terminals. What action should
be take next?
Correct Answer
replace the gas valve
Page 3 of 41
, Question 15
Typical condensing furnaces have an AFUE rating of at least:
Correct Answer
90%
Question 16
A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should:
Correct Answer
check voltage to igniter
Question 17
A technician connects the electrical circuit to an 80,000 BTU gas furnace with a 3-ton
cooling system. The fan motor is rated 1/3 HP @ 120 VAC. What size conductor would
normally be used? (copper conductors)
Correct Answer
12-14 AWG
Question 18
What instrument would a technician use to measure return airflow to a furnace?
Correct Answer
anemometer
Question 19
Type B Vent pipe is constructed with an inner pipe and outer pipe. The inner pipe is
made of:
Correct Answer
Aluminum
Page 4 of 41
Answers 100% Pass
Question 1
Induce draft furnaces have a vent safety switch that should open at ...?
Correct Answer
140 F
Question 2
A GFCI circuit breaker detects:
Correct Answer
current leaks to ground
Question 3
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof,
should...?
Correct Answer
Point down
Question 4
The proper name of the tool used to clean the inside edge of steel pipe is a:
Correct Answer
reamer
Page 1 of 41
,Question 5
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is:
Correct Answer
Temperature on/ Temperature off
Question 6
Burning one cubic foot of natural gas will produce approximately ___ BTU's.
Correct Answer
900-1100
Question 7
What is the purpose of a spoiler screw located on a burner, or adjustable-shutters?
Correct Answer
to mix primary air and gas
Question 8
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor:
Correct Answer
18 inches
Question 9
How much current does a typical flame sensor produce?
Correct Answer
1-30 microamps
Page 2 of 41
,Question 10
The proper name of the tool used to cut the threads of a steel pipe is a:
Correct Answer
die
Question 11
Natural gas piping must be sized to prevent excessive pressure drops. The National
Fuel Gas Code maximum pressure drop allowance is approximately:
Correct Answer
0.35 in WC
Question 12
An inclined manometer measures:
Correct Answer
pressures below 1 in. WC
Question 13
Furnace limit switches are wired in series with the:
Correct Answer
Gas valve
Question 14
While evaluating a gas valve that failed to open, the technician determined that; the
gas valve knob was in the proper position- the thermostat was calling for heat- the
valve is an electric ignition type- continuity of the main gas valve coil was good- and
proper voltage was present at the main gas valve coil terminals. What action should
be take next?
Correct Answer
replace the gas valve
Page 3 of 41
, Question 15
Typical condensing furnaces have an AFUE rating of at least:
Correct Answer
90%
Question 16
A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should:
Correct Answer
check voltage to igniter
Question 17
A technician connects the electrical circuit to an 80,000 BTU gas furnace with a 3-ton
cooling system. The fan motor is rated 1/3 HP @ 120 VAC. What size conductor would
normally be used? (copper conductors)
Correct Answer
12-14 AWG
Question 18
What instrument would a technician use to measure return airflow to a furnace?
Correct Answer
anemometer
Question 19
Type B Vent pipe is constructed with an inner pipe and outer pipe. The inner pipe is
made of:
Correct Answer
Aluminum
Page 4 of 41
